Vehicle drive apparatus

Abstract

A vehicle drive device includes: an engine; a fluid power transmission device; a clutch disposed between an input side member and an output side member in the fluid power transmission device; and a torsional vibration reduction device disposed in a power transmission path between the engine and the fluid power transmission device in series with the fluid power transmission device, wherein when the clutch is put into slip engagement, the vehicle drive device has a minimum value set equal to or greater than zero for a differential rotation speed acquired by subtracting a rotation speed of the output side member from a rotation speed of the input side member and has a minimum value set less than zero for a differential rotation speed acquired by subtracting the rotation speed of the output side member from a rotation speed of an input side inertial body in the torsional vibration reduction device.

The invention claimed is:  
     
       1. A vehicle drive device comprising:
 an engine; 
 a fluid power transmission device; 
 a clutch disposed between an input side member and an output side member in the fluid power transmission device; 
 a torsional vibration reduction device disposed in a power transmission path between the engine and the fluid power transmission device in series with the fluid power transmission device, and a control device configured to control the clutch, 
 wherein, the control device is configured, when the clutch is put into slip engagement,
 to control an engagement pressure of the clutch such that a minimum value is set equal to or greater than zero for a differential rotation speed acquired by subtracting a rotation speed of the output side member from a rotation speed of the input side member and 
 such that a minimum value is set less than zero for a differential rotation speed acquired by subtracting the rotation speed of the output side member from a rotation speed of an input side inertial body in the torsional vibration reduction device. 
 
 
     
     
       2. The vehicle drive device of  claim 1 , wherein the control device is configured to control the engagement pressure of the clutch in accordance with a target value of the differential rotation speed acquired by subtracting the rotation speed of the output side member from the rotation speed of the input side member is set to a value smaller than fluctuation of the rotation speed of the input side inertial body in the torsional vibration reduction device and larger than fluctuation of a rotation speed input to the clutch. 
     
     
       3. The vehicle drive device of  claim 1 , wherein differential rotation between the input side member and the output side member is set equal to or less than 1/2 rotations per second. 
     
     
       4. The vehicle drive device of  claim 1 , wherein a value acquired by dividing torsional rigidity of the torsional vibration reduction device by total inertial mass in a power transmission path from the engine to the clutch is set less than 5000 [rad/sec 2 ]. 
     
     
       5. The vehicle drive device of  claim 1 , wherein the input side member and the output side member are inhibited from being rotated relative to each other during a complete engagement of the clutch.